Power Electronics Europe April/May Issue 2022

INDUSTRY NEWS 15 www.power-mag.com Issue 2 2022 Power Electronics Europe of latching and auto-restart behaviors required by applications such as chargers, adapters, consumer electronics and industrial systems. HiperLCS-2 comes as a chip-set with two devices: the power-device, and the isolation device. The power-device (LCS726x), is on the primary side of the isolation barrier and includes an LLC controller with built-in high-side and low- drivers and half bridge power MOSFETs. The isolation-device (LSR2000), straddles the isolation barrier to facilitate communications to the power-device (primary device). The isolation- device also includes the secondary controller and SR-driver. The HiperLCS-2 is able to operate with nominal frequencies of up to 240 kHz. It offers extremely high conversion efficiency coupled with low-component count and rugged protection features. The chipset complements the HiperPFS-5 ICs. The new dual-chip solution features an isolation device with a high-bandwidth LLC controller, synchronous rectification driver and FluxLink™ isolated control link, alongside a separate half-bridge power device utilizing 600 V FREDFETs with lossless current sensing and high- and low-side drivers. Both devices are housed in low-profile InSOP™-24 packages. This integrated, energy-efficient architecture eliminates heatsinks and reduces component count by up to 40 percent compared to discrete designs. Power supply designs based on the new HiperLCS-2 can achieve no-load input power of less than 50 mW at 400 VDC input and provide a continuously regulated output, easily complying with the world’s most stringent no- load and standby efficiency regulations. HiperLCS-2 devices operate at high efficiency across the load range with dissipation so low that direct heat transfer through the FR4 PCB is all that is required, eliminating heatsinks in adapter designs up to 220 W continuous output with up to 170 percent peak power capability. All HiperLCS-2 family members feature self- powered start-up and provide the start-up bias for a PFC stage using the company’s ICs described above. Secondary-side sensing provides less than one percent regulation accuracy across line and load range and across production variations. Devices are priced at $2.34 respective $3.20 in 10,000-unit quantities. Design example The DER-672 describes a 24 V, 220 W reference design power supply that can operate from 90 VAC to 265 VAC for TV and computer monitor applications. The power supply uses the mentioned CRM PFC front-end with a LLC DC-DC converter operating at 120 kHz for high efficiency power conversion. www.power.com www.power-mag.com LEFT: DER-672 220 W reference design board layout LEFT: DER-672 220 W reference design total efficiency with respect to output power and different line voltages